Each battery in a battery pack is an electrochemical device with a finite life. Individual batteries generally require inspection, maintenance, repair, and replacement in use of the battery pack. Typical measurements include temperature, voltage, current, internal resistance, impedance, conductance, battery condition and the date and time of the measurement. Temperature extremes, alternating ripple voltage, and current may reduce battery life. Batteries may be kept in rooms with controlled temperatures, but it is important to monitor the amount of AC ripple on a battery. As batteries age, their internal resistance increases and that also reduces their life. Other measured parameters include DC and AC voltage and current.
During a test, an operator typically holds a device, e.g. a multi-meter or a battery tester, for measuring and recording. The device has a pair of test leads that extend from a body of the device and terminate at a pair of probes respectively. Another operator manipulates the probes to contact with terminals of a battery under test. As the battery might be placed at a location which is difficult for measurement, extension arms can be attached to the probes to help the operator to reach the battery. Since the operators need to pay close attention to the position of probes, it is inconvenient to check a display of the device frequently. Therefore, there is a need to provide a measurement device which is convenient to prompt an operator of test results.